Clara Robinson was traveling with her family on Christmas Eve.
They left Durant, Oklahoma, and headed to McKinney, Texas, when their car left the road and hydroplaned into a drainage ditch.
First responders removed four people from the vehicle, but Clara and her father, Will Robinson, were swept away.
Officials said he was later found dead after trying to save Clara from the rising floodwaters.
Searchers resumed their search Sunday morning and said they were targeting large piles of driftwood.